| 摘要 |
PURPOSE: An HLEA-B2(High performance IPC Link E1 trunk interface board Assembly-B2) is provided to stably operate a line by containing E1 and redundancy E1 trunk. CONSTITUTION: An E1 trunk matching unit(30-1) executes functions of E1 line coding, AIS(Alarm Indication Signal) transmission and receipt sensing, LOS(Loss Of Signal) sensing, CCS(Common Channel Signaling)/CAS(Channel Associated Signaling) selection, trunk state remote reporting and control, monitoring of E1 frames, and providing a loop-back path for a test. A PLL(Phase Locked Loop) generates E1 trunk frame synchronous signal and all kinds of clocks for a trunk. The PLL is controlled by an EPLD(Embedded Programmable Logic Device). A multitrunk system synchronizer(30-3) is operated in a slave mode using a E1 frame synchronous signal received from the trunk as a reference signal or in a master mode that the PLL generates all kinds of clocks by inner synchronization. A BMPA(BTS Main Processor Assembly) interface unit executes an HLEA-B2 matching function and a modem matching function. A control unit(30-7) supports HDLC(High-level Data Link Controller) interface with a BMPA-B1 board.
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